Water heater



United States Patent [72] Inventor Noboru Yamashita 17. S-Ban, 2-Chome, Eki-Mae. lharagi, 0saka,.lapan [21 1 App]. No. 752,895 [221 Filed Aug. 15, 1968 [45] Patented Oct. 13, 1970 [54] WATER HEATER 3 Claims, 3 Drawing Figs.

[52] US. Cl 122/156 [51] Int. Cl i F22b 13/02 50] Field of Search 122/109, 156,165,166,182

[56] References Cited UNITED STATES PATENTS 142 273 8/1873 Pratt 1. 122/109 1,619,889 3/1927 Scott 122/182 l,804 777 5/1931 Jerome... 122/165X 2,142,626 1/1939 Anderson et a1 122/165X 2,593.032 4/1952 Johnson i 122/182 3,215,124 11/1965 Shoemaker. 122/165 3368531 2/1968 Fehr 122/165X Primary E.raminerKenneth W. Sprague Attorney- Dawson. Tilton, Fallon and Lungmus Patented Oct. 13, 1970 3,533,378

Sheet L of 2 WATER HEATER The present invention relates to improvements in a water heater.

A principal object of the present invention is to provide a' water heater capable of performing efficient heat exchange and having a durable heat exchanger in which deformation of plates due to the pressure of heated water is perfectly prevented.

Another object of the present invention is to provide an efficient instantaneous water heater which is capable of boiling a large amount of water almost instantaneously.

Still another object of the present invention is to provide a structure which is capable of automatically collecting and venting the air sent in along with water and bubbles generated in a water chamber of the boiler when water is boiled, whereby the boiler is prevented from being heated without water which is most dangerous in boilers, thus protecting the boiler from cracks to be developed therein.

Other objects and advantages of the present invention will be readily understood from the following detailed description with reference to the accompanying drawings, in which:

FIG. 1 is a front view of a water heater in accordance with the present invention;

FIG. 2 is a diagrammatic view in section showing the internal structure of a water heater of the present invention; and

HO. 3 is a view in section taken along the line lll-lll in FIG. 2.

Although the present invention will be hereinafter described with respect to a typical embodiment, it is to be understood that the invention is not limited only to such embodiment, but the invention may also reside in all of the substitutions, alterations and equivalents which are involved in the scope of principle of the invention as set forth in the claims and the spirit of the inventor.

Referring to the drawings, an instantaneous water heater of the present invention principally comprises a boiler A having respective means to be later described and a case B for housing the boiler with a suitable heat insulating material (not shown) interposed therebetween.

As clearly shown particularly in FIG. 2, the boiler A comprises a body 2 which is circular in cross section having a combustion chamber 1 in an internal upper portion, a heat exchanging member C in an internal lower portion and a flue opening 17 in the lowermost portion communicating with a chimney l6, and a nozzle 7 of a burner 3 for ejecting a flame from above into the combustion chamber 1, the burner 3 being fixed to a cover 6 detachably attached to the upper opening 4 of the body 2 by flanges 5. Also mounted on the cover 6 is a fan 8 for efficiently forcing the flame ejected from the nozzle 7 into the lower portion of the heat exchanging member C. Around the nozzle 7 is formed an outlet 9 for discharging the blast from fan 8.

it will readily be understood that with the above-mentioned structure, the burner, fan and other attachments can be detached all together by removing the cover 6 and that the upper end of the body 2 is thereby widely opened to facilitate cleaning of the interior of the boiler as by flowing water thereinto. This water is flowed out from an outlet 10 provided at the lower end of the body. in order to facilitate inspection of the state of combustion in the combustion chamber 1 from the outside, there is provided an inspection window 18 in the body 2.

The heat exchanging member C comprises alternately formed flame passages a and water passages b perfectly sealed from the passages a, the passages a and b being formed of combination of metal plates 12 having a suitable thickness formed with a plurality of hemispherical concave and convex portions 11 orderly arranged in ranks and files. Each of the metal plates 12 is so disposed that the vertexes of the hemispherical convex portions 11 thereof may be in contact with those of another plate in facing relation therewith only in the flame passages a. Accordingly, when the water supplied from a water inlet 15 into the water passages b is heated by the flame with resultant pressure of the water acting on the metal plates 12 outwardly, it is quite unlikely that the metal plates 12 are subjected to deformation and that the spaces of the flame passages a are narrowed, since they contact witheach other at the vertexes of hemispheric convex portions. Even a relatively thin metal plate, therefore. can be formed into a strong heat exchanging member which is capable of performing satisfactory heat exchange. Furthermore, with a large number of continuous hemispheric convex and concave portions H, the metal plates 11 provide a remarkably increased heat transfer area to effect high thermal efficiency. It will be seen in FIG. 2 that the flame passages a are formed with slightly smaller clearances in the'lower portion than in the upper, so that even when the hot blast expanded by heating reduces in its volume due to heat exchange as it passes downward through the passages a, there is no variation effected in the total amount of heat given to the metal plates, the passages a being formed narrower toward the lower end; hence the heat exchanging memberc performs uniform heat exchanging action in its entire area from the upper portion up to the lower for efficient heating of water.

As clearly shown in FIGS. 1 and 2, the boiler A is disposed with slight inclination and a hot water outlet 14 is provided at the slanting upper end of a water chamber 13 communicating with the water passages a in the boiler. This is also an important structure of the present invention. It is generally well known that when water is heated in a pan or the like, bubbles are formed. Especially in case water is continuously supplied to a boiler and boiled, a large amount of air, sent into the boiler along with the supply of the water, produces together with the bubbles stagnation of air within the boiler, which results in heating of boiler without water, thereby further developing a crack therein; most objectionable phenomenon.

In accordance with the present invention, the hot water outlet 14 is formed at the upper slanting end of the water chamber 13 in slightly inclined boiler A, so that the air sent therein together with water and bubbles formed in boiling the water are collected at the outlet 14 where the water level is highest to be vented successively upon the discharge of hot water. Thus, the stagnation of bubbles no longer takes place and the above-mentioned difficulties have been overcome.

lclaim:

l. A waterheater comprising an elongated boiler having an internal combustion chamber in an upper portion thereof, said boiler being slightly inclined in upright position, a heat exchanger with gas passages and water passages mounted within the boiler in a lower portion thereof, said heat exchanger comprising a plurality of pairs of generally longitudinally extending metal plates having a plurality of generally hemispheric concave and convex portions, the sheets of each pair being spaced apart with the concave and convex portions of each sheet of the pair overlying the concave and convex portions, respectively, of the other sheet of the pair to provide a water passage therebetween, the pairs of metal plates being constructed and arranged so that the hemispheric convex portions of each pair of plates are in contact with hemispheric convex portions of an adjacent pair to provide the gas passages between adjacent pairs of plates, the gas passages being sealed from the water passages.

2. The water heater of claim 1 in which the concavity and convexity of the hemispheric concave and convex portions, respectively, of each pair is less at the lower portion of the pairs than at the upper portion thereof whereby the gas passages at the lower portion of the heat exchanger are narrower than the gas passages at the upper portion of the heat exchanger.

3. The water heater of claim 1 including a cover detachably secured to the upper end of the boiler, said cover including a fan and a burner having a nozzle for ejecting a gas flame into the combustion chamber, the boiler being provided with a water outlet at the lower end thereof, whereby the boiler may be cleaned by detaching the cover to permit water to flow through the boiler. 

